TRS-80 Model II

TRS-80 Model 16Model 16Model IITRS-80 Model 12Tandy 6000Tandy Model 16Model 12Model II/12/16Radio Shack TRS-80 Model IITRS-80 models 16 and 16e
The TRS-80 Model II was a computer system launched by Tandy in October 1979, and targeted at the small-business market.wikipedia
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TRS-80

TRS-80 Model ITRS-80 Model IIITandy TRS-80
Despite its name, the Model II was not an upgrade of the original (Model I) TRS-80, but an entirely different system.
Following the original Model I and its compatible descendants, the TRS-80 name later became a generic brand used on other technically unrelated computer lines sold by Tandy, including the TRS-80 Model II, TRS-80 Model 2000, TRS-80 Model 100, TRS-80 Color Computer and TRS-80 Pocket Computer.

Tandy Corporation

TandyTandy ComputersTandy Corp.
The TRS-80 Model II was a computer system launched by Tandy in October 1979, and targeted at the small-business market.
That year, Tandy was the leading Unix vendor by volume, selling almost 40,000 units of the 68000-based, multiuser Tandy Model 16 with Xenix, and began selling all computers using the Tandy brand because, an executive admitted, "we were told by customers that the Radio Shack name was a problem in the office".

Scripsit

Some were produced in-house (like the Scripsit word processor), others licensed and branded as Radio Shack products (like the Profile database), and still others marketed by Radio Shack, such as VisiCalc.
This version basically matches the functionally of the normal Scripsit for disk-based platforms such as the Model II, Model 12, and Model 16.

Xenix

SCO XenixMS-XenixTrusted Xenix
The Model 16 can run either TRSDOS-16 or TRS-Xenix, a variant of Xenix, Microsoft's version of UNIX.
Tandy more than doubled the XENIX installed base when it made TRS-XENIX the default operating system for its TRS-80 Model 16 68000-based computer in early 1983, and was the largest UNIX vendor in 1984.

Motorola 68000

68000M68000MC68000
The Model 16 added a 6 MHz, 32-bit Motorola 68000 processor and memory card, keeping the original Z80 as an I/O processor.
At its introduction, the 68000 was first used in high-priced systems, including multiuser microcomputers like the WICAT 150, early Alpha Microsystems computers, Sage II / IV, Tandy TRS-80 Model 16, and Fortune 32:16; single-user workstations such as Hewlett-Packard's HP 9000 Series 200 systems, the first Apollo/Domain systems, Sun Microsystems' Sun-1, and the Corvus Concept; and graphics terminals like Digital Equipment Corporation's VAXstation 100 and Silicon Graphics' IRIS 1000 and 1200.

VisiCalc

Some were produced in-house (like the Scripsit word processor), others licensed and branded as Radio Shack products (like the Profile database), and still others marketed by Radio Shack, such as VisiCalc.
Other ports followed for the Apple III, Zilog Z80-based Tandy TRS-80 Model I, Model II, Model III, Model 4, and Sony SMC-70.

Multiplan

Microsoft Multiplan
Tandy offered multi-user word processing (Scripsit 16), spreadsheet (Multiplan), and a 3GL "database" (Profile 16, later upgraded to filePro 16+), as well as an accounting suite with optional COBOL source for customization.
Multiplan was released first for computers running CP/M; it was developed using a Microsoft proprietary p-code C compiler as part of a portability strategy that facilitated ports to systems such as MS-DOS, Xenix, Commodore 64 and 128, Texas Instruments TI-99/4A (on four 6K GROMs and a single 8K ROM), Radio Shack TRS-80 Model II, TRS-80 Model 4, TRS-80 Model 100 (on ROM), Apple II, and Burroughs B-20 series.

Home computer

home computershomehome computing
The TRS-80 Model II was a computer system launched by Tandy in October 1979, and targeted at the small-business market.

Mainframe computer

mainframemainframesmainframe computers
It claimed that the computer was "ideal for a small business, and also 'just right' for many time-consuming jobs within larger businesses", including those with mainframes or minicomputers.

Minicomputer

minicomputersmini-computermini
It claimed that the computer was "ideal for a small business, and also 'just right' for many time-consuming jobs within larger businesses", including those with mainframes or minicomputers.

CP/M

CP/M-80CP/M operating systemBDOS
It sported 80x25 text and a single-sided 500k 8" floppy drive, and either 32 or 64k of RAM, along with two RS-232 ports and a Centronics-standard parallel port. The video memory could be banked out, so that the entire 64K address space could be used for main memory. Unlike most computers, it had no BIOS ROM except a small boot loader (the BIOS was loaded off the boot floppy). Because of this and the use of port I/O, almost all of the Model II's memory could be used by software. The Model II ran the TRSDOS operating system (renamed to TRSDOS-II starting with version 4.0) and BASIC. The different disk format and system architecture made it impossible to run Model I/III software on the Model II, thus it never had as much available. This was somewhat mitigated by the availability of the CP/M operating system for the Model II from third parties such as Pickles & Trout. Unlike the Model I/III, the Model II's memory map is compatible with standard CP/M-80.

Western Digital FD1771

WD1770FD17811793
The floppy drive included with the Model II was a Shugart SA-800 full-height, single-sided 8" drive; like most such drives, it spun continuously whether the disk was being accessed or not and the spindle motor was powered directly off the A/C line. The floppy controller in the Model II was a double-density, soft-sector unit based on the WD 1791 floppy controller. Like with the Model I/III/IV, boot disks on the Model II required Track 0 to be single density. CDC drives were used for the floppy expansion module.

IBM 3740

3740 Data Entry System
The disk format on the Model II closely followed the IBM 3740 standard, which specified 77 tracks, 24 sectors per track, soft sector formatting, and a sector size of 128 bytes for a formatted capacity of about 250k, however the Model II had a double density controller, so the disk format used 256 byte sectors and formatted capacity was about 492k.

RCA

Radio Corporation of AmericaRCA CorporationRCA Astro
The video display in the Model II is similar to the Model I. A 12" B&W television CRT is used; the monitors were supplied by RCA and Motorola. However, the Model II's video circuitry was significantly improved in the interest of better picture quality, as one of the criticisms of the Model I was that the included monitor was merely an RCA television set with the RF, IF, and sound stripped out. The Model II, in contrast, used a dedicated monochrome composite monitor with higher-quality and better-adjusted components than the modified TV set provided with the Model I. The text display on the Model II was 80x24 rather than the Model I/III's 64x16 text and also added lowercase letters, one major feature that the Model I was lacking (originally; an upgrade was available later). In addition, it could be operated in 40x24 text mode. The character set in the Model II was somewhat different from the Model I/III.

Motorola

Motorola, Inc.Motorola Inc.Motorola Semiconductor
The video display in the Model II is similar to the Model I. A 12" B&W television CRT is used; the monitors were supplied by RCA and Motorola. However, the Model II's video circuitry was significantly improved in the interest of better picture quality, as one of the criticisms of the Model I was that the included monitor was merely an RCA television set with the RF, IF, and sound stripped out. The Model II, in contrast, used a dedicated monochrome composite monitor with higher-quality and better-adjusted components than the modified TV set provided with the Model I. The text display on the Model II was 80x24 rather than the Model I/III's 64x16 text and also added lowercase letters, one major feature that the Model I was lacking (originally; an upgrade was available later). In addition, it could be operated in 40x24 text mode. The character set in the Model II was somewhat different from the Model I/III.

S-100 bus

S-100IEEE-696S100 bus
The Model II was similar to an S-100 machine in that it featured a passive backplane with eight expansion slots; four of these were normally occupied by the CPU card, floppy controller, keyboard/video card, and RAM.

Scott Adams (game designer)

Scott AdamsScottScott Adams Adventures
Despite being designed primarily for business or operating factory equipment, the Model II did have a handful of games available; notably the Scott Adams Adventure series were offered for it.

Infocom

feeliesfeelieStu Galley
In addition, CP/M versions of Infocom text adventures would run.

Perry, Michigan

PerryCity of PerryPerry City
It could hold an additional three 8" disk drives or up to four 8.4Mb hard drives (the Model II allowed three external floppy drives to be daisy-chained to it). In 1981, the 64K Model II computer was $3,350 and the "primary unit" 8.4Mb hard disk another $4,040 by mail-order from Radio Shack's dealer in Perry, Michigan; MSRP in the company's own stores was higher.

Fortran

Fortran 77Fortran 90FORTRAN IV
Microsoft made available its Fortran, Cobol and BASIC compilers, as well as its MACRO-80 assembler.

BASIC

BASIC programming languageGOSUBcompiled BASIC
Microsoft made available its Fortran, Cobol and BASIC compilers, as well as its MACRO-80 assembler.

Wayne Green

inCiderinCider Magazine
Wayne Green estimated that sales of the Model II were about 10% of the Model I, discouraging third-party developers from creating software for the more expensive computer; the small software library, in turn, discouraged sales of the Model II.

Zilog Z80

Z80Z80AZ-80
The Model 16 added a 6 MHz, 32-bit Motorola 68000 processor and memory card, keeping the original Z80 as an I/O processor.

Killer application

killer appkiller appskiller-app
Tandy admitted that it should have encouraged third-party software development, which resulted in the killer app VisiCalc for the Apple II.

Apple II

Apple 2AppleApple II Plus
Tandy admitted that it should have encouraged third-party software development, which resulted in the killer app VisiCalc for the Apple II.